One of the questions I am asked from time to time is why friendships seem to change as we get older. In my experience, it’s not personal. Research suggests that adult friendships are shaped by three important factors: proximity, timing, and energy.

Proximity
Friendships are built through repeated interaction. When we were younger, school, university, or sport naturally placed us alongside the same people every day. Research by Jeffrey Hall suggests that close friendships develop over many hours of shared time and experience. As adults, those opportunities become far less frequent, making it harder to build and maintain close relationships.

Timing
As we move through life, our priorities naturally diverge. One friend may be raising young children, another may be building a business, while someone else is caring for ageing parents or travelling the world. You may still value one another deeply, but your lives no longer move at the same pace. Even colleagues who get on exceptionally well may rarely meet outside work because they are in very different stages of life.

Energy
Friendships also evolve as we evolve. Perhaps you stop drinking alcohol, take up long-distance running, become more politically engaged, or simply begin valuing quieter weekends over late nights. None of these changes are inherently good or bad, but they can alter the activities, conversations, and experiences that once held a friendship together.

I think understanding these three factors has helped me see friendships differently. Sometimes a friendship fades because life changes and not because either person has done something wrong. Perhaps the goal is not to hold on to every friendship forever, but to appreciate the role each person has played in our journey while remaining open to new connections as we continue to grow.